The basic physical systems of a country's or community's population, including roads, utilities, water, sewage, etc. These systems are considered essential for enabling productivity in the economy. Developing infrastructure often requires large initial investment, but the economies of scale tend to be significant.
Lesson Summary. Both phylogenetic trees and cladograms help show the relationships between different organisms, but only phylogenetic trees have branches that represent evolutionary time and amount of change. These were formerly based on physical characteristics, but are more accurately based on genetic relationships.iologists use cladograms and phylogenetic trees to illustrate relationships among organisms and evolutionary relationships for organisms with a shared common ancestor. Both cladograms and phylogenetic trees show relationships among organisms, how alike, or similar, they might be.
Reading phylogenetic trees: A quick review (Adapted from evolution.berkeley.edu) â¢ A phylogeny, or species/evolutionary tree, represents the evolutionary relationships among a set of organisms or groups of organisms, called taxa (singular: taxon) that are believed to have a common ancestor.ypes of Biological trees â¢ Taxonomy trees, like the one hosted at NCBI, are hierarchies; thus classification is determined by position or rank within the hierarchy. It goes from kingdom to species.â¢ Phylogenetic trees represent evolutionary relationships, or genealogy, among species.